diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index ccc9db9..935781c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -49,7 +49,22 @@ jobs:
 
       - name: Test
         run: |
+          set -ex
           # Test as an unprivileged user (short options)
           dfuzzer -v -n org.freedesktop.systemd1
           # Test as root (long options + duplicate options)
           sudo dfuzzer --verbose --bus this.should.be.ignored --bus org.freedesktop.systemd1
+          # Test logdir
+          mkdir dfuzzer-logs
+          dfuzzer --log-dir dfuzzer-logs -v -n org.freedesktop.systemd1
+          # Test a non-existent bus
+          if sudo dfuzzer --log-dir "" --bus this.should.not.exist; then false; fi
+          # Test object & interface options
+          dfuzzer -v --bus org.freedesktop.systemd1 --object / --interface org.freedesktop.DBus.Peer
+          sudo dfuzzer -v --bus org.freedesktop.systemd1 --object / --interface org.freedesktop.DBus.Peer
+          # - duplicate object/interface paths
+          dfuzzer -v --bus org.freedesktop.systemd1 --object xxx --object yyy --object / --interface org.freedesktop.DBus.Peer
+          dfuzzer -v --bus org.freedesktop.systemd1 --object xxx --object yyy --object / --interface zzz --interface org.freedesktop.DBus.Peer
+          # - test error paths
+          if dfuzzer -v --bus org.freedesktop.systemd1 --object aaa; then false; fi
+          if dfuzzer -v --bus org.freedesktop.systemd1 --interface aaa; then false; fi